Control device and components thereof for electromotive drive for winding bobbins for yarn and the like



April 27, 1965 o. H. BLUNCK ETAL 3,130,584

CONTROL DEVICE AND COMPONENTS THEREOF FOR ELECTROMOTIVE DRIVE FORWINDING BOBBINS FOR YARN AND THE LIKE Filed Nov. 6, 1962 15 Sheets-Sheet1 J0 venfors Wumaul-Li km f 1 M.

Ap 1965 o. H. BLUNCK ETAL 3,180,584

CONTROL DEVICE AND COMPONENTS THEREOF FOR ELECTROMOTIVE DRIVE FORWINDING BOBBINS FOR YARN AND THE LIKE Filed Nov. 6, 1962 3 Sheets-Sheet2 P" 2 1965 o. H. BLUNCK ETAL 3,180,584 CONTROL DEVICE AND COMPONENTSTHEREOF FOR ELECTROMOTIVE DRIVE FOR WINDING ROBBINS FOR YARN AND THELIKE Filed Nov. 6. 1962 3 Sheets-Sheet 3 hvenfor: 5 165/122, M

' CONTROL DEVECE AND COMFQNENTF; THERE- Germany, a corporation ofGermanyFiled Nov. 6, 1962, Ser. No. 235,620

8 Claims. (ill. Zeb-d) The present invention relates to a control devicefor the electromotive drive 'of winding bobbins for threads made ofsynthetic material, wool, cotton or a similar material in conjunctionwith three-phase current driving motors, and further employs centrifugalgovernors which are adjustable to various speeds during the running ofsuch motors, for the'purpose of achieving a preferably constant windingspeed and thus a preferably constant stretching oruniformity of thethread.

If, while winding up the thread, the diameter of the bobbin is increasedand the winding speed or the peripheral speed shall remain constant, therevolutions per minute of the bobbin must be accordinglyreduced. Acentrifugal governor is driven by a follower roller which bears againstthe bobbin and is thereby driven by friction. The centrifugal governoris set to a certain speed; if this speed is surpassed by a certainamount, the electric contacts of thecentrifugal governor open, whereasthe contacts of the centrifugal governor close if the speed of rotationfalls by a certain amount below the pro-adjusted speed. As the diameterof the bobbin increases and the speed of rotation of the bobbinremains'constant, the follower roller would rotate accordingly faster.This, however, is'lnot permitted by the centrifugal governor, since itimmediately switches off when the speed of rotation of the; followerroller increases. In this way, as the diameter of the bobbin increasesand the speed of rotation of the centrifugal governor remains constant,the speed of rotation of the wind-up "bobbin is more and more reduced somagma winding speed remains constant. 7 c t 1 It is one object of thepresent invention to provide a control device, which solves this controlproblem. The coni trol is better, the smaller the distance between theupper a and lower speeds of rotation in a given speed range and thesmaller the intervals of the switching actions are. It willbe understoodwithout further explanations that the quality of the control isdependent on the quality of the 7 electric switching means used for thecontrol device, on the acceleration and deceleration of the drivenmasses which take place during the control, and on therapidity of the iswitching action.

A device is already known, wherein a centrifugal governor is directlyarranged upon the shaft of a follower United States Patent ingmembersperiodically bridges the series resistance of a motor branchcircuit of a direct current motor or a single phase alternatlng'currentmotor. Since the electric contacts of the centrifugal governor open orclose in accordance with the speed of rotation of the follower roller,such act upon the supply circuit of the drive mot-or for the wind-upbobbin or upon an auxiliary circuit coupled with the supply circuit, forexample, by means of a relay or 7 another suitable switching element, sothat by virtue of the switching-in and switching-out the seriesresistance of the drive motor the desired regulation occurs.

Acontrol device hasalso been proposed for application with three-phasecurrent short-circuit rotor motors. Such three-phase current shortcircuit rotor motors have proven "ice commutators nor slip rings.Furthermore, they have proven to be advantageous in that their speed ofrotation short-circuit rotor motor is employed, as the drive motor.

for the winding bobbin, the three conductors of such motor leading toits three phases are connected with three actuatable switch members,which are synchronized with respect to one another for simultaneousinterruption of the current flow in such three phases.

These switch members are controlled by the centrifugal governor drivenby the speed-regulated shaft. The three windings of the stator ofsuchthree-phase. current shortcircuit rotor motor are arranged in starconnection and the neutral or star point is connected to earth. Theswitch members for the synchronous control coupled to the threeconductors can be formed as a single relay provided with three workcontacts, or comprise three transductors or electronic switches.Furthermore, capacitors and/or resistorsmay be arranged in the currentcircuit between the working contacts of the switch memberand the phasewindings of the three-phase current motor for spark eX- tween theswitching operations became longer and inaccurate. In such a knowncontrol device the centrifugal contact governor directly actuated therelay without any increase in power, whereby a large drop of potentialwas created over the centrifugal contact governor, while opening thecontacts so that a corresponding voltaic are or spark was. drawn. Thisburning-off very soon cause-d changes on the contact surface andtherefore a disadjustment of the centrifugal contact governor.

Furthermore, a very disturbing drawback of the proposed cont-rol devicewas the lack of a flywheel mass as, during the control operation, thewinding bobbin which is of rather light weight was accelerated too fastwhen the current was switched on and decelerated too fast whenthecurrent was switched out, sothat the control curve was undesirablysteep at the start and between the regulating steps. Furthermore, a.quite considerable expenditure of switching members i-s'necessary inorder to control all three phases of the three-phase currentshort-circuit rotor motor by means of switching members.

It is another object of the present invention to provide a controldevice which improves the controlfor the drive of winding bobbinsfor-threads made of synthetic material, wool, cotton or similan'material by a three-phase current short-circuit rotor motor by reducingthe expenditure of switching members and by-improving the latter.

It is a further object of the present invention to provide a controldevice whichprovides the possibility to reduce such an expenditure ofthe switching members in that with one embodiment of the invention onlytwo phases of the three-phase current short-circuit rotor motor areconnected through the switch members, whereas the third phase isdirectly connected with the power supply or network. With theinterlinking of the three stator windings of the three-phase currentmotor the desired control effect is faultlessly achieved through thecontrol of only two phase windings which are provided with suitablyarranged switch members. If the two of the phases are switched out, thenthe motor is switched over. The star point remains free of thepotential. If the interlinking of the three stator windings is made inform of a star connection, the star point must not be connected toearth; only the casing of the motor is connected to earth.

(,3 No switching off of the two phases takes place by the contacts 28and 29, rather the insertion of a resistance on each. of the two phases.The current is thereby reduced and the number of revolutions is reduced.The switching lonand oifof the machine is brought about 'by theswitchl32.

.In the known device the centrifugal governor is rigidly connected withthe, follower roller.. A considerable dis,

' advantage of such an arrangement residesin the fact. that only asingle speed can be controlled or achieved with such a rigidly arrangedcentrifugal governor, and neither an adjustment because of a deviationin the winding speed.

occurring during operation nor a readjustment .to' another speed rangeis possible. Only with the condition of rest of the machinecan thecentrifugal governor be adjusted,:

or exchanged for another, in order to obtain the desired speed ofoperation. Periods of inactivity of the equip ment are of courseundesirable because they result in a reduction of production capacity.

Such a disadvantage of known devices is effectively overcome byemploying the. teachings of the present invention wherein thecentrifugal governor is provided with a friction wheel or roller whichis driven by a friction disk operatively secured to the follower roller,and wherein'the centrifugal governor is displaceablyarrangedradiinvention to provide an improved control device for the iprovide an'improyed control device: for winding bobbins ally to'thefriction disk. By means of a finely threaded spindle and a scaleprovided for the radial displacement,

it is possible to achieve a sensitive adjustment ofthe wind-up speedduring the running of the machine.

It has already been mentioned that the small flywheel mass of the drivenparts is a very disturbing feature of the known and/ or proposedtcontroldevices for thedrive J of wind-up bobbins. This causes undesirableoscillations of the running speed at 'the'start of the-winding operationwhen the bobbin or spool'is empty, which'cannot be avoided in spite ofthe quickest control-impulses. The large starting torque of thethree-phase current motor rej sults, in conjunction with small gyratingmasses or working loads of the rotating members, in undesirable speedavoided in accordance with the present invention in that between thethree-phase current motor and the drive .of

thebobbin there is coupleda flywheel which is connected 1 with the motorby means of an elasticor resilient coupling. The elastic coupling incooperation with the flywheel absorbs. the hard cut-in or startingimpacts, stores the received energy, and slowly returns the same; Thus,

the starting curve becomes less steep inasctmt, the control amplitudesbecome smaller and also gentler inascent;

The relay is actuated by the centrifugal contact governor vby means of acontact protection circuit. Thus, the i amplitudes and exceptionallyhigh stress reversal of the members secured to the shaft. Thisdisadvantage can be 1 current load on the contacts of the centrifugalcontact p governor'which. has up to now been several milliarnperes isnow reduced to 2 or 3 microamperes. Now, the current load no longerresults in a wear of the contacts of. p

the centrifugal contact governor, the life of the lattergdependingsolely on the mechanical deformation of the' contacts. The contacts ofthe centrifugal contact gover-v nor operate faultlessly withoutbreakdown spark'and without sticking together. i

The contact protection circuit which in itself has been known, but hasnot yet been used for this purpose, allows to connect only a relay oflow inductivity, since high in ductivities would result in backfiring'in thecold cathode tubes which are used in the contact protectioncircuit.

These backfirings are avoided by the arrangement of a rectifier parallelto the relay.

7 The relay being used is an easily switchable special relay, thedetailsof which are described further below.

Accordingly, it is yet another object of the present in vention toprovide a control devicefor the electromotive drive of winding bobbinsfor threads which permits of a substantially constant wind-up speed anda substantially electromotive drive of wind-up spools or bobbins forthreads, which is highly reliable in operation and permits of speedcontrol of the winding operation with a high degree of accuracy and(within a very exacting speed range.

' It is yet'another object of theypre'sent invention to provide animproved control device fort the electromotive drive of winding bobbinsfor threads and the like, whichdrive isa three-phasecurrentshort-ci'rcuit'rotor motor.

it is also a further object of thepresent invention to including meansfor absorbing the starting impacts, to prevent or minimize; theoccurrence of undesirablespeed am plitudes and high stress reversalof'memberssecured to the drive motor shaft. a 1

it is also a still further object of the present invention to provide:an improved control device for. winding bobbins, including a controlcircuit for actuatinga relay or suitable arrangement, whichwcontrolcircuit includes a contact protection circuit andis responsive to the;action- 'of a centrifugal governor.

Itisyet an object of the present-invention to provide an improvedcontrol device :for winding bobbins, which con-'- trol device employs aneasily actuatable-relayr permitting of a quick sequence of switchingoperations and having:

a relatively longroperating life. 7

Still furtherobjects and the entire scope of applicabilw ity of thepresent invention will become apparent'fronr the detailed descriptiongiven hereinafter; it should be understood, howeven'that thedetailed-description and specific examplesQwhile indicating preferredembodiments of the invention, are given by-way-ofillustration only,

since various changes andmodifications within the spirit and scope :ofthe invention willbecome apparent to those skilled in the art fromthis.detailed description.

present invention will be clearly understood in connection with the.accompanying drawings, in which? FIGURE 1 is a perspective view of thecontrol device according'tothe present inventionfor the-drive of'aWind-up bobbin; l i

FIG. 2 illustrates a circuit diagram of the control de-r vice with thedrive according to FIG.11- and according to the present inventionemploying a two-phase switching of the threeephas'e current shorbcircuitrotor motor and a control circuitactuated by a centrifugal governor;

FIG. 3 is a side elevationcf the adjustalblei centrifugal governor,partially in cross-section; and I FIG. 4 is a section along the'lines:.4-'4 of FIG; 3 showing details of. the centrifugal switchthereof...

Referring now to the drawings.and more"particularly to FIG.'1, wherein adrive is illustratedffor a windsup bobbinwith the desiredcontrcl'device, the threeephase current. short-circuit rotor motor ll'driv'esqthe wind-up spool or bobbin 6 by means of the coupling disk-2,the

elastic or resilient coupling means 3,. the flywheel mass, 4

and the shaft 5. A follower roller -7 which rolls-or rides on theperiphery of the' wind-upbobbin 6 is providedwith a friction disk 8 in.engagement with the friction wheel 9 ofthe centrifugal. governor 11mounted on the axle 10.

The operation of thezcentrifugal governor ll-the two contacts 12 and 13of whichare electrically connected with the control circuit will bedescribedfurther below 7 with referenceto the FIGS. 3 and 4.'

The; follower roller 7 is rotatably mounted on the rocker arm or beam l4whch pivots about the-axle 15 during continuous contact of the followerroller 7' with the Wind- The thread package. The cross spindle l6 andthe block 17 serve to drive the thread guide 19 moving to and fro on theguide rail 18 and being employed for winding the thread 24 by means ofthe follower roller 7 in a familiar manner on to the wind-up. spool orbobbin 6, distributed over the entire width of the latter. The crossspindle 16 is driven from the fiy wheel 4 by means of a belt pulley 21,the belt 22 and the belt pulley 23. The details of the drive for thethread guide 18 do not constitute a part of the present invention, sothat no further descriptions thereof are believed necessary. A box 24contains the electric switch members provided for the operation and thecontrol of the drive according to the present invention, the controlcircuit being actuated by the centrifugal governor 11 with a contactprotection circuit, and the switching relay. The operation of the box 24is described in conjunction with FIG. 2.

Referring now to FIG. 2, the electric circuit diagram illustrates thedesired control device for the drive of a wind-up bobbin 6. Thethree-phase current short'circuit rotor motor Lthe coupling disk 2, theelastic or resilient coupling members 3, the flywheel mass 4, the windupbobbin 6, the follower roller 7, the friction disk 8, the friction Wheel9, the centrifugal governor 11'', and the thread 29, according to FIG. 1are illustrated only schematically.

The three phases U.V.W. of the three-phase current short-circuit rotormotor 1 are interlinked in star connection, and the star point is notconnected to earth but the casing of the motor lis connected to earth.In the two phases R and S of the three-phase current network there areprovided series'resistors 25 and 26, the phase T beingdirectly-connected with the motor 1. Furthermore, there is provided arelay 27 with two change-over contacts 28 and 29. The change-overcontact 28 lies in the phase R and serves to connect or bridge theseries resistor 25, whereas the change-over contact 2% lying in thephase S serves the same object for the resistor as. The'relay 27 isactuated by the centrifugal governor ll through the control circuit 30with the contact protection circuit. A rectifier 31 is connectedparallel to the relay 27 in order to short-circuit the reverse voltagesoccurring when the relay is deenergized. Prior to placing the controldevice into operation the two change-over contacts 28 and 2) of therelay 27 are located in a position in which the series resistors 25 and26 are not arranged in the path of the current flow. I

vBy means of a switch 32 and three fuses 33 the three phase currentshort-circuit 'rotor motor 1 is connected directly with the three phasesR, S and T and the earth conductor 0 of the three-phase current networkand thus switched in. The motor ll starts running whereby the wind-upspool or bobbin 6 will be correspondingly driven. Due to the Winding. ofthe thread 2%, which takes place in consequence of the foregoing action,the diameter of the thread package woundonto the bobbin 6 increases. Asa result of the continually increasing diameter of the wound threadpackage with constant speed of rotation of the bobbin 6, the rotationalspeed of the follower roller 7 continually increases. At the same timethe speed ofjrotation of the centrifugal governor 11 increases. Thecontact members 12 and 13 of the centrifugal governot 11 which have beencorrespondingly adjusted are caused to open upon reaching apredetermined upper speed of rotation, whereby the current flow producedin the control circuit as and flowing through the relay 27 isinterrupted. Consequently, the contact members 28 and 29 of the relay2'7 simultaneously open, so that the resistors 25 and 26 are nowconnected with the two phases R and S. This results in a reduction ofthe voltage in these current circuits and, therewith, a reduction of thespeed of rotation of the drive motor I. The resistors 25 and 26 are sodimensioned that, upon their switching in,

a rest current remains and the speed of rotation of the. motor 1decreases to about 20% of its nominal value. As a result, the speed ofrotation of the bobbin 6 and the speed of rotation of the followerroller '7, the speed of the latter of which is dependent upon therotational speed of the bobbin 6, is reduced until the centrifugalgovernor 11 again closes its centrifugal contacts 12 and 13.

It is possible to employ other switching members in place of the relay2'7 providedwith the switch contacts 255 and 2?; for example,premagnetized iron-core choke coils (transductors) or electronicswitches,

The provision of series arrangements consisting of resistors andcapacitors designated by the reference numerals 34, '35 and 3 betweenthe three phases U.V.W. of the stator winding of'the motor 1 and theneutral conductor illustrates a possible arrangement for sparkextinguishing and switch unloading. The same purpose is served by theseries arrangements consisting of a resistor and a capacitor with thereference numerals 37, 38, and 39, id connected with the switch contacts23 and 29 of the relay 27. I

Now, the details of a possible construction for the control circuit 3bwith the contact protection circuit are de scribed. A substantiallysimilar ty e of control circuit, but however not employed in combinationwith a centrifugal governor and not with the general arrangement hereindescribed, is disclosed in the German Patents 1,049,498 and 1,054,177,in which Otto l-linrich Blunck, one of the applicants, has been named asthe inventor, and owned by the assign-2e of this application- Referringnowto FIG. 2, it will be appreciated that a suitable alternating voltageis app-lied to the inlet terminals B and B of the control circuit 3t).With the centrifugal contacts l2 and 13 in open position after thecentrifugal governor H has reached its upper speed of rotation to whichit has been preadjusted, and with positive phase, that is B is positiveand B negative, almost the entire voltage is applied between'the anode Aand the cathode'K of the glow discharge tube GR (e.g. cold cathodetube).

The rectifiers G and G connected in" parallel to the glow dischargetubes GR and GR serve as voltage dividers, since the rectifier G in thisphase is high-resistive, whereas in contrast thereto the rectifier G islow-resis tive.- On the other hand,-practically the entire voltage dropat the high-ohm resistors R R and R appears as the ignition voltagebetween the control electrode S and the cathode K of-the glow dischargetube GR, so that with a suitable relationship of R :(2R +R the glowdischarge tube GR ignites. The current flows from this glow dischargetube through the relay 27 and the low resistive rectifier G of thetransformer T. Y

With a negative phase, that is terminal B is negative and terminal Bpositive, the glow discharge tube GR ignites;

The manner of operation of 'thecircuit with negative current (invertedalternating current) flowing there..

through which is similar to that produced by a fu1l-wave rectifier.There is thus produced a sawtooth-like current in which no longer everysecond tooth is missing. Thus the relay 2'7 is caused to respond whenthe contacts 12 and 13 are open. tacts 28 and 29 are caused to switchover, the resistors 25 and 26 are connected with the phases R and S ofthe motor circuit, and the motor 1 is caused to decrease its speed ofrotation until the centrifugal governor 11 runs so slowly thatitscontacts l2 and 13 again close.

If the contacts 12 and 13 are closed the'potential difference betweenthe control electrodes 5 or S and the cathodes K or K' is reduced, sincethe voltage now only drops across the high-ohmresitsors R and R or R andthis phase to the terminal B of Upon. response of relay 27 the con-.

- 1? R 2 the result can be achieved that the voltage drop at .the

resistor R is not-sufficient for igniting the glow discharge 7.

tube. GR. Consequently, the current flow through the glow discharge tubeGR is interrupted and the relay 2.7 is released, since the currentflowover, the contacts 12. and 13 of the centrifugal governor 11 is onlyequal to Additionally, the control circuit' several microamperes. 39 isprovided with a capacitor C coupled bet-weenthe center=tap M of thesecondary winding of the transformer T and the common junction orcontact point P and con nected with the relay 27 and the rectifiers Gand G.

This capaictor C is particularly efiective in preventing.

With a suitable selection of the relationship R1IR2 false ignition ofthe glow discharge. tubes as well as malfunctions in the circuit. Therectifier 31 which is coupled across the relay 27 serves to interceptthe backlash potential or counter-voltage resulting upon current intertubes makes such that the full. operatingvoltage is applied to the glowtube to be ignited, whereas the other glow tube is short-circuited. Inorder to achieve a safe response of the relay independently of the phaseposition, a capacitor is arranged between the common switchpoint of therelay and the two rectifier on the one side and the potential middle ofthe applied alternating current,

Each ofthe glow discharge voltage on the other side. tubes has controlelectrodes and theswitch means of the control circuit include a relayhaving two simultaneous 1y actuable work con-tacts. The contactprotection circuit includes further resistor means with the controlelectrodes of each of the glow discharge tubes, and also a rod 41 andthus the centrifugal governor 11 are displaced in direction of the axle.10. A second knurled nut lei-serves as a locking nut inorder tosecurethe threaded rod 41 and thus thecentrifugal governor 11 in the positionadjusted.

- Arranged between'the. centrifugal contact governor 11 and the rocker.arm 14- is' agscale member 47 having divisions or markings thereon inaccordance with the circumferential speed of the wind-upbobbin or spool6.

The farther the friction Wheel 9 on the friction disk 3 is movedoutwards, theslower the wind-up bobbin 6 must rotate and the lower willbe the circumferential speed thereof with the same adjustment of thecentrifugal contact governor 11L v The centrifugal governor 11 isprovidedwith two con tacts 12 and 13 of which, .forexample, the contact12 is arranged on the free end of a fixed leaf spring or so calledregulator spring 48'Wl'tl1 the; balance weight 49. The pre-load or biasof the. regulator springi and thus the'speed to be controlled can beadjustedby means of' a set screw 50.

The contacts 12; and 13 are connected with the two slip rings 51 and 52which are insulatedly: arranged upon the axle 16. In order to provide aconductive connection transformer having a primary and a secondarywinding and connected with input terminals of the control circuit,

on the axle 10. In this manner the rotational movement of the-followerroller 7 is effectively transmitted to the. I

friction disk?) and the friction wheel 9-thereby driving the centrifugalgovernor 11. In the desired embodiment illustrated the centrifugalgovernor 11 is provided in the extension of the axle 19 with a threadedrod 41 mounted upon thehousing of the centrifugal governor 11 andthereby supporting the centrifugal governor 11 in the bearing block 42.This bearing block 42. is rotatably mounted upon the rocker. arm 14 bymeans of a hinge 43, so that the axle 10 of the centrifugal governor 11and the #axle of the follower roller 7 are disposed vertically upon eachother and the friction wheel 9 is free to ride or roll on the frictiondisk 8. The centrifugal governor lilis maintained in this position bymeans of thespring 44 which'at the same time provides for urging thefriction wheel 9 against the friction disk 8, which is required for afaultlessoperation. The radial adjustmentof the centrifugal governor 11with respect to the friction disk 8 trolling the winding operationof'the material to be wound '70 in order to obtain aniapproximatelyuiform wind-up between the rotating contact '12 and 13and the.stationary controlcircuit 34), there are provided two carbon brushes 53and 54 which. press upon the two slip rings 51' andi5-2 and are coupledwith :the electric control circuit 35%) through the electric conductors55 and 56.

The relay 27 is an easily actuatable special relay which has becomeknown under the designation reed relay and was described', for examplebyR. A. E. Pursey in the article Sealed Contact Reed Relays in-Electronics on July 31, 1959. 1 Such. relays have contacts hermeticallysealed in aglass tube,'the ferromagnetic contact reeds of which switchunder the influence of-a magnetic field. The glass tube containsinitslower part a certain volume of metallically' highly pure mercurywhich risesupwards on the suitably formed contaotireed'due totheacaipillaryv effect and continuously wets the contact surface with athin film of mercury; This film of mercury on the confact is renewedwithfevery switching operation. The

switching point, being protected. by an'atmosphere of. inert gas andcoated with "a thinfilm of mercury, is not' exposed to any adverseexternal influence so that, inadditionto a relatively low contactresistance, a very high. number of switching operations without contactchatterand a very long operating life of the contact tube areguaranteed.

It is obvious that the powerrequired for switching the relay isdependent upon the number of the switch contacts to be moved. Sinceonly-two switch contacts are required with a two-phase control, thepower required for carrying outthe switchingoperationis lower than with,three switch contacts, the latter being required for the switching ofthree phases. 7 I

The application of such a relay in the desired control deviceaccordingto the FTGS. ,l and 2 results in the following advantages: Thelower the moving mass of the relay is, the faster. will be the sequence.ofthe switching operations, the shorter will bethe intervals between theswitching operations and the better will be thecontroloperation itself.Up .to now it has beenlpossible to'obtain a control accuracy up to 10%of the speed of rotation adjusted,'now'a control accuracy of 0.3% ori0.l5% of the. speed of rotation is achieved.

'It should thus be appreciated that the described control arrangement isreadily suitable for effectively conspeed and stretching of thematerial. Furthermore, the winding speed can be adjusted during thewinding operation, without requiring stoppage of .the machine.

While we have disclosed one embodiment of the present invention, 'it isto be understood that this embodiment 9 is given only by way of exampleand not in a limiting sense, the scope of the present invention beingdetermined by the objects and the claims.

We claim: p

1. A control device for the electromotive drive of winding bobbins forthreads made of synthetic material, wool, cotton or similar material,comprising a winding bobbin receiving thread to be wound thereathree-phase current short-circuit rotor motor including a stator havingthree phase windings and a casing having a motor shaft,

means connected with said motor shaft for rotating said winding bobbin,-

an electric circuit connected with said three-phase windings of saidstator of said three-phase current shortcircuit rotor motor,

said electric circuit including a control circuit,

a centrifugal governor electrically coupled to said control circuit,

resistor means in two phases of said three-phase Windings renderedoperative in response to a predetermined speed of said governor,

follower roller means engaging and driven by said winding bobbin andoperatively connected with said centrifugal governor,

said centrifugal governor including means for opening said controlcircuit in response to a predetermined speed,

said control circuit including a contact protection circuit means andalso including means actuable upon opening said control circuit uponreaching said predetermined speed of said centrifugal governor forconnecting said resistor means with said two of said three-phasewindings,

power supply means connected with said three-phase windings,

said three-phase windings of said stator of said threephase currentshort-circuit rotor motor being connected in star arrangement, and

said motor casing being grounded,

whereby a predetermined uniform speed of winding of said thread isbrought about.

2. The control device, as set forth in claim 1, wherein said actuablemeans of said control circuit comprises a relay having twosimultaneously aotuable work contacts, and switching means in two phasesof said motor circuit for switching in said resistor means. 3. Thecontrol device, as set forth in claim 2, wherein said relay has sealedcontacts and mercury wetting. 4. The control device, as set forth inclaim 3, which includes a rectifier disposed in parallel with saidrelay. 5. The control device, as set forth in claim 1, wherein saidmeans connected with said motor shaft for rotating 10 said windingbobbin comprises a flywheel secured to said motor shaft and an elasticclutch operatively connected between said flywheel and said three-phasecurrent short-circuit rotor motor.

6. The control device, as set forth in claim 1, wherein said contactprotection circuit includes a pair of glow discharge tubes connected inpush-pull arrangement, and

a rectifier disposed in parallel with each of said glow discharge tubes.

7. The control device, as set forth in claim 6, wherein each of saidglow discharge tubes has control elec trodes,

said switch means of said control circuit include a relay having twosimultaneously actuable work contacts,

said contact protection circuit further includes resistor meansconnected with said control electrodesof each of said glow dischargetubes, and

said rectifiers are connected with said relay by means of a commonjunction. 7

8. The control device, as set forth in claim 7, wherein said contactprotection circuit further includes a transformer having a primary and asecondary winding and connected with input terminals of said controlcircuit,

said secondary winding has a center-tap, and

acapacitor connected between said common junction and said centeratap ofsaid secondary winding of said transformer.

2, 1959 (K1 21g 4/05), 2 pp. spec., I sht. dwg.

MERVIN STEIN, Primary Examiner.

RUSSELL C. MADER, Examiner,

1. A CONTROL DEVICE FOR THE ELECTROMOTIVE DRIVE OF WINDING BOBBINS FORTHREADS MADE OF SYNTHETIC MATERIAL, WOOL, COTTON OR SIMILAR MATERIAL,COMPRISING A WINDING BOBBIN RECEIVING THREAD TO BE WOUND THEREON, ATHREE-PHASE CURRENT SHORT-CIRCUIT ROTOR MOTOR INCLUDING A STATOR HAVINGTHREE PHASE WINDINGS AND A CASING HAVING A MOTOR SHAFT, MEANS CONNECTEDWITH SAID MOTOR SHAFT FOR ROTATING SAID WINDING BOBBIN, AN ELECTRICCIRCUIT CONNECTED WITH SAID THREE-PHASE WINDINGS OF SAID STATOR OF SAIDTHREE-PHASE CURRENT SHORTCIRCUIT ROTOR MOTOR, SAID ELECTRIC CIRCUITINCLUDING A CONTROL CIRCUIT, A CENTRIFUGAL GOVERNOR ELECTRICALLY COUPLEDTO THE SAID CONTROL CIRCUIT, RESISTOR MEANS IN TWO PHASES OF SAIDTHREE-PHASE WINDINGS RENDERED OPERATIVE IN RESPONSE TO A PREDETERMINEDSPEED OF SAID GOVERNOR, FOLLOWER ROLLER MEANS ENGAGING AND DRIVEN BYSAID WINDING BOBBIN AND OPERATIVELY CONECTED WITH SAID CENTRIFUGALGOVERNOR, SAID CENTRIFUGAL GOVERNOR INCLUDING MEANS FOR OPENING SAIDCONTROL CIRCUIT IN RESPONSE TO A PREDETERMINED SPEED, SAID CONTROLCIRCUIT INCLUDING A CONTACT PROTECTION CIRCUIT MEANS AND ALSO INCLUDINGMEANS ACTUABLE UPON OPENING SAID CONTROL CIRCUIT UPON REACHING SAIDPREDETERMINED SPEED OF SAID CENTRIFUGAL GOVERNOR FOR CONNECTING SAIDRESISTOR MEANS WITH SAID TWO OF SAID THREE-PHASE WINDINGS, POWER SUPPLYMEANS CONNECTED WITH SAID THREE-PHASE WINDINGS, SAID THREE-PHASEWINDINGS OF SAID STATOR OF SAID THREEPHASE CURRENT SHORT-CIRCUIT ROTORMOTOR BEING CONNECTED IN STAR ARRANGEMENT, AND SAID MOTOR CASING BEINGGROUNDED, WHEREBY A PREDETERMINED UNIFORM SPEED OF WINDING OF SAIDTHREAD IS BROUGHT ABOUT.